- Remove X11BASE and replace it with LOCALBASE, since the former is
deprecated.
- Silently ignore if included files are not found. This way we do not
depend on the FreeBSD ports tree being installed.
- Add definitions for LOCALBASE and PREFIX in case they are not given
from the included files.
- Change MANDIR to ${PREFIX}/man instead of ${PREFIX}/share/man, to
better match reality.
ok marco